Jack Lew, President Obama’s pick to run the Treasury Department, is being pressed by Senate probers to reveal details of a $1.4 million personal loan he got from New York University when he was a top exec at the school, The Post has learned.

NYU listed the loan on its tax filings, which showed the outstanding balance dropping to $673,000 by 2005, his final year at the university.

Lew left his post as executive vice president of the school to join Citigroup, leaving the final status of the loan unclear — and prompting a member of the Senate Finance Committee to raise questions.

As The Post revealed last week, Lew has come under fire in the Senate for leading NYU at a time when it was accused of steering student loans to “preferred lenders,” including Citigroup, in exchange for “kickbacks.”

NYU settled with the state attorney general in 2007 and paid a fine without admitting wrongdoing.

Lew left NYU to become an exec at Citigroup — a tenure that has also drawn criticism because he got nearly $1 million in compensation in 2008 around the time the bank got a taxpayer bailout.

“Please describe the terms of the loan including interest rate, minimum payment requirements, term, and the purpose of the loan,” Grassley wrote.

“Please describe how the loan was repaid and whether any portion of it was forgiven. If the loan interest rate was below market, or if the loan was forgiven, did you report appropriate amounts as income to the IRS?”

A person familiar with Lew’s time at the university said: “NYU provided housing assistance to Mr. Lew, as the university has done for other senior officials and faculty. NYU reported income related to the housing assistance on Mr. Lew’s W-2 forms, and he paid all taxes that were due.”

The person didn’t respond to questions about who paid off the loan.

The loan also raised questions for NYU staff.

“Given the curious circumstances of his departure, we would really like to know if Lew repaid that loan and if so, on what terms — especially in an institution whose students are so horribly indebted,” Mark Crispin Miller, a professor of media studies, told The Post.

Lew, who is still likely to be confirmed, also faces scrutiny for his NYU salary, which at $907,000 was more than university president John Sexton’s.